Korotkoff sounds

Diagram illustrating the phases of Korotkoff sounds.

Korotkoff sounds are the sounds that medical professionals listen for when they are taking blood pressure using a sphygmomanometer and a stethoscope. These sounds are named after Dr. Nikolai Korotkoff, a Russian physician who first described them in 1905.

Phases of Korotkoff Sounds

Korotkoff sounds are divided into five distinct phases, which are used to determine the systolic and diastolic blood pressures.

Phase I

Phase I is characterized by the first appearance of faint, clear tapping sounds that gradually increase in intensity. The onset of these sounds corresponds to the systolic blood pressure, which is the maximum pressure in the arteries during the contraction of the heart's ventricles.

Phase II

In Phase II, the sounds become softer and may have a swishing quality. This phase occurs as the cuff pressure is reduced and the blood flow in the artery becomes more turbulent.

Phase III

Phase III is marked by a return to crisper and louder sounds. This phase indicates that the blood flow is becoming less turbulent as the artery is more open.

Phase IV

Phase IV is characterized by a distinct muffling of the sounds. This phase is sometimes used to determine the diastolic blood pressure in children.

Phase V

Phase V is the point at which the sounds disappear completely. This is used to determine the diastolic blood pressure in adults, as it indicates the pressure in the arteries when the heart is at rest between beats.

Clinical Significance

Korotkoff sounds are crucial for accurately measuring blood pressure, which is an important indicator of cardiovascular health. Abnormal blood pressure readings can indicate conditions such as hypertension or hypotension, which require medical attention.

Related Pages

• Blood pressure measurement
• Hypertension
• Sphygmomanometer
• Stethoscope